Self-winding clock and time switch



Aug. 18, 1936.

w. MUIR ET AL SELF WINDING CLOCK AND TIME SWITCH Filed Sept. 23, 1932 5 Sheets-Sheet 1 E I I INVENTORS Aug. 18, 1936. w. MUIR ET AL SELF WINDING CLOCK AND TIME SWITCH Fil'ed Sept. 23, 1932- 5 Sheets-Sheet 2 A llg. 18, 1936. w Mum ET'AL 2,051,455

SELF WINDING CLOCK AND TIME SWITCH Filed Sept. 25, 1932 3 Sheets-Sheet 5 Patented Aug. 18, 1936 PATENT OFFICE SELF-WINDING CLOCK AND TIME swrrcn William Muir, Bristol,

Burlington, Thompson Clock 00., ration of Connecticut and Herbert Snow,

Conn., assignors to The H. 0.,

Bristol, Conn, a corpo- Application September 23, 1932, Serial No. 634,600

4 Claims.

This invention relates to improvements in spring motors adapted to be wound by another motor or motors, and particularly of the type suitable for use as the prime movers of time 5 telling clocks, circuit controlling time switches,

combinations thereof, and for analogous purposes.

Particularly, the present improvements concern spring motors which are wound by electric l0 motors and more especially by electric motors having a rotary armature acting intermittently to perform the winding.- The spring of such motors commonly acts as a reservoir of power derived from the intermittent brief fast running of the electric motor through a winding train and played out in the slow continuous running of a time train retarded by a time keeping escapement.

Self-winding movements acting'broadly on the above principles are well known in the art and there is also well known the expedient resorted to for simplicity and compactness, of placing the slowest moving gear of the time train in concentric relation to the slowest moving gear of the winding train, to be supported, if desired, on the same spindle, and between which two gears may be located a spiral ribbon spring or band spring to serve as the power spring above referred to. Either end of such spring may be connected to be impelled by rotation of the winding gear and the other end connected to impel the time gear. Relative movement between the said two gears thereupon becomes necessary to elfect a winding or an unwinding of the spring. Proper stop means definitely limit this relative movement to a pretermined extent which extent may exceed a full turn of relative movement of either gear. To control the periodicity and the duration of the intermittent 40 winding action of such motors, it is common to provide electric contacts to be operated au tomatically at regular predetermined intervals by some moving part of the time train to start and stop the winding action of the electric motor, or which may be opened by the action of some moving part of the winding train to stop the winding.

Heretofore, in periodically acting, self-winding movements of this nature there has been provided an arrangement of such contacts and the associated elements which insures that during normal operation when once put into service by expert attention, a designed degree of running down or unwinding of the power spring shall cause the winding contacts to close and remain closed until the electric motor has run long enough on each such occasion to fully replenish the power which the spring has expended since the preceding automatic winding and without causing an overwinding, so that in the normal operation of the clock or time switch there shall be no aggregation nor depletion of winding in the spring above or below definite prescribed limits constituting the operating range. There has also been provided a degree of winding always existent in the spring below this designed operating range and placed there by an initial winding operation when the clock is placed in service by the attendant making the installation; This amount of. initial winding plus any unexpired portion of the normal winding range constitutes at any given time the sum total of reserve power which the spring possesses and determines the length of time the movement would run before the spring power is entirely depleted should the electric motor fail to wind at its proper time due to run down batteries or other trouble.

There are certain short-comings in all movements'of the'above type with which we are familiar, which preclude their entrance to modern markets and uses which would benefit otherwise from the simplicity and compactness of this type of self winding movement. Among these shortcomings are the requirement for expert attention to the initial winding feature requiring a separate manual switch to be supplied for this purpose alone and a clear understanding of how to make use of this switch to avoid damage to the movement by attempted overwinding-the lack of a suflicient possibility of initial or accumulative winding to constitute a desirable amount of reserve in case of current failure and the former absence of any construction or manner of operation of the contacts acting automatically to start and stop the winding to make such contracts suitable to handle circuits exceeding battery voltages in the form of mechanism highly desirable for acting upon such contacts herein herein illustrated and lending itself to the simplicity and compactness which has formerly characterized the low voltage self-winding movements referred to.

Accordingly, it is an object of our invention to avail of the desirable features and proven advantages of the type of self-winding movements above described and to incorporate improvements which shall make them available to wider fields of use. 7

To this end our improvements aim to provide a self-winding movement which shall have in addition to its normal operating range of spring winding, a sub-range, or initial range, of winding accomplished by mechanical means of a character to make this sub-range or reserverange practically unlimited by factors other than commercial desirability and which shall make this reserve range variable at will as to amount, by the simple'change of the number of teeth in a gear. v a

Our improvements further aim to provide a .winding control switch which "shall end it's.

movement in a contact making position whenever failure of current or failure of the electric motor to wind results in a-running down of the movement spring below its normal operating stage of winding and intoits reserve power stage of winding.

Our improvements further aim to provide a winding control switch so acting that if the spring runs down from its normal operating range of winding'into its reserve power range of winding, the contacts will so act or succese 7 switch or clock. .44).

sively .act to restore'the spring to. its normal operating stage of winding and keep it there as a fully automatic operationindependent of at.- tention from the user.

Our' improvements further aim to provide a winding control switch so automatically acting that when incorporated in a clock or time switch and shipped to the user direct or through the trade no expert services nor attention to. printed directions shall be necessary to insure the cor-,

rect installation and initiate. the use of same in the hands. .01? an uninformed purchasen.

.Ourlimprove'ments further aim to eliminate the manual pre-winding. switch heretofore pro.- vided for operation by the user before service could be obtained from'the seli, winding time Our improvements further aim to provide. a control switch of novel construction and characterized by a novel, principle of operation to insure a snap action both to make and to break a circuit when used in'whatever: connection.

Our improvements. further; aim to provide a wi din control w c actuated; by re t v ly s o oving pa s..wh ch-. ha l co sti ute ar fthearbor. on which the power springis located and to permit adjustment in the tension. of; said spring while the parts. mounted .on said; arbor are assembled in place.

These improvements further makepos'sible a fully automatic time switch organization wherein a timing power spring and a switch actuating power spring are both automatically maintained wound by the same winding motor whereeach of saidpower springs are provided with over-wind and under-wind preventers eliminating allj manual, attentionito their operation in practical use.

In the drawingsf. Fig. 1 is a front view of a combined timetelling clock and time; governed circuit. controller em o y re nt: m mr m n s r a dial and indicating parts being broken away to better illustrate the mechanism.

Fig. 2 is a plan view looking downward on Fig. 1 certain parts being shown in section on the horizontal plane 22 of Fig 1.

Fig. 3 is a perspective view looking from the rear at the complete device of Fig. 1, the clock face which surrounds the setting dial being omitted and certain parts broken away for clearness.

Fig. 4 is a fragmentary view of a possible arrangement of certain pins and stop parts associated with the spring winding gear of Fig. 2 with the epicyclic gears omitted; The parts are viewed as they would be seen in Fig. 3 and drawn on a larger scale.

Fig. 5 is a view corresponding to Fig. 4 with the epicyclic gears included. 7

Fig. 6,on a correspondingly large scale, is a perspective view of the floating arm which is located between the parts shown in either Fig. 4 or 5 and the switch. operating cam of Fig. 7'.

Fig. 7 is a correspondingly enlarged view of the switch operating cam as it partly appears in Fig. 3. r

Fig. 8 shows diagramatically the switch cam, floating arm, and various stop pins of Figs. 4, 6 and '7 with one of the gear carried pins of Fig. 4. omitted for explaining certain advantages of these improvements, these partstogether with the electrical, spring-leaf, contacts which they operate being positionedas they are left at the end of the automatic winding action. a

Fig. 9 shows the parts of Fig. 8 as they are positioned after onegturn of running down action of the spring motorwhen automatic winding 3 Fig. 4, in preventing a condition such as that sho nn.

Fig. 1-2, shows an intermediate position. of the parts of Figs. 8. tov '11 inclusive wherein one spring-leaf. contact: is againstthe insulative portion andthe-other is against-theconductive portion. of the switch operating cam.

The completeclock and time switch organization comprises the following main'parts. power spring I0 to actas a reservoir of. power furnished by the intermittent running of an electric motor II and to play out ,this power through the continuous running of a time train governed by a chronometer escapement representedas a unit by'the ordinal II in Fig. 1; a circuit controlling mechanism including the leaf contacts l3 and I4 andtheir operating cam I5- which, withassociatedparts, acts both electricallya-nd mechanically to govern the time and extentof the windingaction of-motor'll as well as to limit the unwinding action of" spring I0;- a current switching mechanism l-8- adapted to be automatically operated by a second power spring contained within the drum 'lfi" of Fig. ,3 which also acts as a reservoir for power stored therein by the intermittent running of motor ll;-and

. a suitable clock face l'l.;preferably' with time telling hands and associated with adjustable time determining trip means 8l-82 to, efiect the periodi automatic action: of the last mentioned current switching mechanism at predetermined times of day.

It will be understood that omissions and substitutions for the above designated main groups of parts may be resorted to extensively inside the objectives and accomplishments of the present improvements which are more particularly concerned with the self winding features of the time movement employed and the particular groups of parts here illustrated are chosen to show a useful embodiment of the invention. They will, therefore, be referred to briefly, followed by a more detailed description of the electrical and mechanical parts which govern the self winding action.

Referring to Figs. 1, 2 and 3, the power spring In of the band, or spiral, type, operates between a winding wheel 25 and a time wheel 26 on the center arbor 2'5, being retained for convenience closely adjacent to winding wheel 25 by the drum disc 28 which is rigidly secured to wheel 25 by posts 29, to one of which posts the outer end of spring I!) is anchored,the inner end being anchored to a pin 35 in arbor 21. The drum structure, comprised of wheel 25, posts 29, disc 28 and its hub 3|, turns loosely on the arbor 21 within positive limits prescribed by certain stop parts illustrated in Figs. 4 to 7 inclusive'whose function will later be described. The time wheel 26 is fast to arbor 2'! and may comprise the slowest moving gear of a time giving train.

Arbor. 2? is given a front bearing in the front main frame plate 35 to which a rear main frame plate 36 is secured by posts 3? and the rear plate 36 supports an auxiliary frame plate 38 by means of posts 39 which auxiliary plate affords a rear bearing for the arbor 2?. Also supported on the front plate 35 by posts 4| is a clock face H hereinafter referred to.

Upon suitable occasions the winding wheel or gear 25 iscaused to turn in a clockwise direction as viewed in Fig. 1 (or in a contra clockwise direction as viewed in Figs. 3 to 5, and Figs. 8 to 12) for the purpose of winding the spring [6 whose outer end travels therewith, and is' so turned by the intermittent running of an electric motor H, which for the purposes of this invention may be a self starting motor of either the synchronous, induction, or direct current, types, or of any other kind'capable of automatically starting when current is supplied to it and of running at either constant or variable speed until its current supply is cut off. Between the motor II and winding wheel 25 is a train of simple, speed-reducing gears consisting of. the pinion 46 fast to the armature shaft 41 of the electric motor, the gear 48 meshing with same and fast to the spindle 49 as is pinion 56, the gear 5| meshing with pinion 50 and fast to the spindle 52 as is pinion 53, and the gear 54 meshing with pinion 53 and fast to spindle 55 as is pinion 56 which meshes withthe winding wheel 25, all of the foregoing spindles having front and rear bearings respectively in the frame plates 35 and 36.

Any form of time train and chronometer escapement may be employed to govern the rotation of the time wheel 26 fixed to arbor 27 so that this arbor may be propelled by spring H1 at a suitable speed for the purpose to be served thereby,in this application, one revolution in one hour, and'arbor 2'! will travel in the same direction 'of rotation that the winding gear 25 revolves for winding the spring l0, as'the turning of arbor 21.is in the nature of a follow-up movement with relation to the winding action of wheel 25 for lettingo-fi the power stored by the latter in the spring I0. For illustrative purposes I have shown as the chronometer escapement employed the unitary assembly of balance wheel, hair spring, verge, and escape wheel carried by the base I2 screwed to the front face of the frame plate 35 shown in Fig. 1, the escape wheel spindle 60 extending to the rear of plate 35 and there carrying the pinion 6! as shown in Fig. 3. Another spindle 62 carries the gear 63 in mesh with pinion SI and also fixedly carrises the pinion 64. Still another spindle 65 carries the gear 66 inmesh with pinion 64 and also fixedly carries the pinion 61 in mesh with the time wheel 26. The parts just described constitute the time giving train which governs arbor 21 to revolve once in one hour.

In the useful application illustrated, arbor 27 performs the'dual functions of driving a conventional minute and hour hand for telling the time of day and of simultaneously impelling a setting dial and associated adjustable trip members 8!82 mounted concentrically therewith. The minute hand 10 is made fast to the extreme forward end of arbor 21. The hour hand H has the usual frictional mounting on a sleeve 12 immediately surrounding the arbor 21 and to which is fixed at its rear end the gear 13. In the usual fashion gear 13 is driven by a pinion 14 which, together with an idler gear I5 has a pivotal bearing on the front frame plate 35 and turns in unison with gear 15 which latter is in mesh with the pinion l6 fast to arbor 21, the preferred ratio being a total reduction of one to twelve whereby the hands 15 and H sweep the conventional clock face H to tell the time of day.

Also deriving its power from pinion 15 .fast to arbor 27 is the graduated dial 853 which, together with the setting levers 8| and 82 is frictionally clamped against a shoulder 83 on an outer sleeve84 by' means of the friction washer 85 and the thumb nut 86, sleeve 84 carrying at its rear end the gear 81 whose friction slippage relative to sleeve 84 is permitted by the friction washer'88. The idler gear 89 and the idler pinion 90 have a pivotal bearing on the front frame plate 35 and turn in unison to deliver power from the pinion 16 to the gear 81 and preferably in the ratio of one to twenty-four whereby the dial 8!) will rotate in the same direction as the clock hands 10 and H at a speed of one revolution irltwenty-four hours. These parts are of conventional structure and most i clearly shown in Fig. 2.

The function of the adjustable setting levers 8| and 62 is to at predetermined times cause the reciprocatory movement of the trip lever l9, lever 8| carrying the ear I60 and lever 82 carrying the ear ID! for this purpose. Trip lever l9 operates the escapement pawl I02 in unison therewith so that as lever I9 is depressed by the slow passing either of ear I88 or of ear IOI the downwardly extendingend of pawl I02 permits one tooth of the switch controlling star wheel I03 to escape, whereupon the star wheel advances a short distance contra-clockwise in Fig. 1 until the tooth of said star wheel which is upwardly disposed in Fig. l is intercepted by the end of pawl H12 which extends to the left, it being understood that star wheel I93 is constantly under tension of "a spring contained within the ratchet drum l6 (see Fig. 3) which constantly urges the star wheel, to rotate, contra elongated to provide for the switch 1blades 105 imember, or double-ended blade J05. :In-the posi-' "tion shown in Fig. 1 this blade conductively,

bridges'a stationary contact clip I06 at the-left and a similar contact clip I01 at the right, iboth clips being mounted in insulated relationto the main frame'plate and in electrical connection with suitable binding ;posts 108 and 1:09. It will be noted that the clips I96 and I! have oneend continuing to bridge the clips after the :pre-

-liminary short distance escapement of star wheel I03 referred to above. After the second and full escapement theiblade I will "be vertically disposed in Fig. 1 thus acting at each quarter turn alternately to make :and to break the circuit between the binding posts Hi8 and I09, each making-action and each breakingaction being effected by the travel of each setting lever 8| and 82, respectively, as it engages and finally passes the terminal portion of trip lever 19.

.Means ."for automatically keeping the spring within ratchet barrel'lfi sufliciently wound ito be ready at all times to effect the escapement of starwheel I03 in the manner described consists 1n anchoring the outer end of this spring to the drum l6 and the inner end to the switch shaft- H0 so that sh aft H0 will tend'to itravel-in the same direction that :drum 16 is turned which action winds-the spring. Referringvto 3 the means for winding the switch spring automatically may further reside in .the winding lever .HI pivoted concentrically :with shaft H0 and free to reciprocate within limits determined by theheart ishaped cam l I 2 which is fast. .to-spindle at the rear of the frame plate 36, lever HI being urged constantly upward :to rest against cam M2 .by the spring ,3. :Each turnz-of cam H12 -as driven by the winding movement of the electric motor ll, depresses'lever I'll which :acts

through the winding 'pawl 114. to advance one or more ratchet teeth of the-drum YIB :under the retaining pawl 14:5 whichho'lds the wind .thus

. imparted in successive small increments to :the

drum l6 and thus to -,the power spring of the switch. Pawl H4 is urged against the ratchet teeth by a spring H6 and pawl H5 :is urged against the ratchet teeth by -a spring il-lil, the latter pawl being fixedly pivoted upon anysuitable portion of the frame. The auxiliary frame plate H8,'mounted;on the rear mainframe plate 36, gives bearing to therear end =01 the switch shaft 1 ID and convenient room for .the ratchet drum H5 at the rearof the'main frame plate.

' A third binding post for wiring Lconnectionappears at .9 in Fig. 1. From :the illustrative scheme of wiring connections: shown inZ-Fig. I21, the two supply wires marked "Line are :seen to each be connected :respectively to :binding.:posts I08 and H9, while :the two wires-comprising'the circuit to be controlled by the switch :blade' trolled switch, of "which the-blades .105 :are apart, might be constructed as a double-pole, .doublebreak switch, in which case the flow :of current .through irboth of the line and load :wires would be interrupted :by this switch; butsince the draw- I ings show the switch :as .merely :a'single-pole, double-.breakswitch, the binding post H9 serves merely as ;a convenient means of deriving .:con-

*nection to both sides 'of the line for the wires and I;2'| carrying current to :the electric The :motor wire MI runs directly ,to 7

connecting the other contact to the motor winding .to complete the :circuit .to the motor when contacts AB and :M .are closed.

brings ms to a description .of the -features illustrated :in Figs. 4 to '12, inclusive; wherein V the before-mentioned spring-leaf contacts l3,.and

H, carried by and in insulated .relation to :a

frame bracket 22, :their operating cam |:5, -wind- 'ing wheel or ggear '25,..and .arbor 21 are :among the parts shown. Figsm8 tolZshow' these parts in :various operating positions as they appear when viewed'rfrom the rear end'of arbor :71 and of actual preferred size corresponding to their scale in Figs. 2 and L3. Figs. 4 to 6 show the parts approximately double in size and viewed in perspective to correspond with the direction in which the "parts are viewed in Figure .3.

fI-hewindinggear 25 may carry one oraboth of V .the two pins and J16 as shownin Figs. 4 and '8 to 11. Close to cgear'25,"thearbor 21carthe diametrically disposed :pin I21. tClose-to ipin l 2-] ,1 arbor 21 acarriesithe iloosely'rotatableifioat mm 428 aintowhose path of 3rotati0nthe pins I25 and I26 project. 'Whereboth these pins'areused, the possible movement of float arm 'l28'relative to gear '25 :is limited by "its iloose play between these .twozpins (-seesli'ig. 11-). Next to thezfioatarm 418, .arbor -21 loosely carries "the switch cam- 15 comprised of a metallic hub 129, its Loam shaped body of insulating *material l5 and the stop pin I30 disposedjparallelztoitsaxiszof rotation. .Riveted to the surface :of .the insulating body =15 and projecting circumferentially therebeyond, so as to comprise a -.part of the effective periphery .of the cam I15 isaaconductive piece I3l iadaptedxto con-.

ductively bridge contacts 13 and 14' in certain positions and'toreceivezand deliver each of said contacts with a snap action owing to its shape as :related to the step shape of :the .adjacentporthe winding, the parts I28 and 15 also being movable in the same direction by the .pin I21 in arbor '21 :during the slow time-keeping, runningdown'action of spring I10 while *the winding gear 25 and its carried pin I25 stand still; It will further rbe seen that while .float arm 128 can pass :neither of pins I25 nor I 30, these :two pins may freely pass each other 'except for the interference of said ifloa't arm as an intermediary, and also that'pin I 21 in'arbor 2 1 mm freelypass the'.winding:pin i25imt Willa-engage and can znot pass the .cam pin I30. With this'understanding of the mechanical relationship, Fig. 8 shows the parts positioned as they are left at the end of an automatic winding action of the electric motor II. The motor II has stopped running for the reason that the spring-leaf contact I4 has just been permitted to drop off the undercut terminus of the conductive piece I3I, thus breaking the electrical connection from the line wires to the winding motor II. Owing to the considerable reduction in the winding train including the pinions or gears 46, 48, 50, 5|, 53, 54, 56, 25, the winding gear 25 and its carried pin I25 will remain where it is left at the time the motor I I stops running immovable in response to any rotative force that can be exerted upon it by the power of spring I0.

The continuous running of the time giving or chronometer train 6|, 63, 64, 66, 61, and 26 now permits the slow contra-clockwise rotation of the arbor 21 and consequently of the pin I21. In Fig. 9, the spiral or broken line indicates that this arbor pin IZ'I has completed one full turn of running down action which brings it to the same position as in Fig. 8, the winding pin I25 meanwhile standing still. "However, the arbor pin I21 following an initial idle portion of its said travel has picked up the cam pin I30 and by impelling it has caused cam I5 to rotate'less than a complete turn but sufficiently for the leaf contacts I3 and I4 to both be projected onto the conductive piece I3l, one at a time and with a snap action as forced upwardly and then passed by the spur I32 of the insulative body I5. Electrical connection is thus established from the line wires to the electric motor II which begins to wind at this point. It may be noted that the floater arm has stod still during the running down action from the positions of Fig. 8 to the positions of Fig. 9 for lack of anything to impel or displace it, but that in Fig. 9, the cam pin I30 has rotated so as to come up on the opposite or left side of floater arm I28 with the result that if current had failed, or if the motor II did not perform its designed winding action at this point for any other reason, the continued contra-clockwise rotation of pin I21 with the turning of arbor 21 would from this point impel the float arm I28 idly for nearly a second full turn of the arbor 27 to the position of parts shown in Fig. 10 at which time the float arm I28 would bring up against the winding pin'I25 and be positively stopped thereby together with all the time keeping parts because of the immovability of pin I21 except through the running of the motor II as heretofore explained. But here it will be seen that contact has not been re-established between the leaf contacts I3, I4 because of the failure of the conductive piece I 3| to recontact same before the rotation of cam I5 becomes thus posi-' tively checked. A condition thus exists where upon resumption of an interrupted current supply through the line wires, the winding motor I I could not pick up and wind because the contacts I3 and I4 have been automatically left open.

To remedy this undesirable condition, and to provide that at all times the permissible running down of the time movement in the absence of designed periodic winding shallleave the parts ready to automatically pick up and wind and thereafter keep themselves designedly wound, I have provided the second pin I26 whose function will be apparent from Fig. 11. Because pin I26 is fixedly spaced from pin I25 and can turn only when and as pin I25 turns, it is plain from Fig.

11 that if the electric motor should fail to wind at the position of parts shown in Fig. 9, not enough further movement of floater arm I28 could take place, in the continued running down,

to deliver the contacts I3 and I4 from off the conductive piece I3I of the cam, this floater arm bringing up against the second'pin I 26 which like pin I25 is immovable except through the running of the electric motor II. Contacts I3and I4 are thus assuredly left closed as all time keeping parts of the movement come to rest, and. are ready to pick up. and resume automatic winding and normal operation by the mere supplying of current through the line wires. This important function and result might be accomplished by other means such as by varying the arcuate extent of the thickness of the floater arm I28 in relation to the arcuate extent of the conductive piece I3I on cam I5 about the circle of action of these parts, but the preferred means of introducing the second pin I26 here illustrated possesses certain advantages and is to be understood as merely illustrative of the principle of provisions by which this needed result may be accomplished.

Considering now thelength of time a self wound clock or time switch of this character can continue running in the absence of the designed periodic automatic winding, due to current failure or other causes, it will be seen that in Figure 10, where only the winding .pin I25 is employed, nearly two full turns of arbor 21'constitutes the maximum running capacity under power of spring I6 should the electric motor II fail to wind. vIn point of time, this is something less than two hours duration of running. under spring power alone. The'addition of the second winding. gear pin I 26 whose function has been described reduces this spring power maximum running period to only slightly more than one hour. Either of these periods is an undesirably small length of time that a self wound time piece or time switch shall run under spring power alone in the event of the failure of its electric winding mechanism. Fig. 5 accordingly shows a novel. expedient which may be resorted to to retain the simplicity. and compactness of the self-winding control mechanism heretofore described while increasing to almost any amount the length of time the movement may continue operating under spring power alone without electric winding, within of course, the power limits of the spring which drives the time .train. Some initial tension in the power spring I0 must in good practice be always unusable, namely, that tension placed in the spring before the assemblage of the parts shown in Figs. 4 to '7. But the range of spring winding and unwinding above this initial and operatively unused amount up to the full wound condition of the spring may be fully availed of, if desired, by the simple provision of the epicyclic gears of Fig. 5.

In Fig. 5, the pin I25 alone, or supplemented by the pin I26 when desired, for the respective purposes of pins I25 and I26 of the other figures of the drawings, may be carried on a freely rotatable dog arm I35 loosely confined between the arbor pin I21 and the winding gear25'. Fixedly turning with dog arm I35is thepinion I 36. In mesh with pinion I36 is the epicyclic gear I31 loosely rotatable'on the pivot stud I38 carried by winding gear 25'. be given one greater or one less number of teeth than gear I3! or any gear ratio may exist between these two epicyclic gears which preferably shall permitthese gears to beof somewhat simi- Pinion I36 may lat diameters while revolving at such relative speeds that a. given point on one gear comes into co-incidence with a given point on the other gear only after a plurality of revolutions ing with the eifect'of causing dog arm I35 and winding gear'25' to travel in unison by positive propulsion onebythe other in whatever direction the pins I39v and I40 may have effected the locking of the epicyclic train. It will be understood this locking may take place in both directions after the permissible number of turns have'takenplace'whereby pins I39 and I40 retreatfrom their locking. engagement and whereby they'r'againarrive at locking engagement in the opposite" direction of. relative turning.

The introduction of the 'epicyclic gears I36 and I 31. will be understood to in no way alter "the purposes and functions of the parts shown in- Figs. 4. to 12' inclusive other than to increase 7 the amount of relative movement. between wind-'- 7 ing gear 25andi the arbor 2:1 by any desired num- 30* ber of turns additional to this; relative movement as. permitted by: thev simple two.- pins I25, I20ca1 ried directly by' gear 25 shown in Fig, 4; a This increased number of relative turns, how ever; is: a measure of: the reserve capacitywhich may be wound into the spring III for permitting the; clock and the time switch to continue their normal operation forone or more days if desired under the power of spring ILO' alone even though: no windingof this spring by the electric motor "I I; takes place; at the designed intervals; Nordoes. the introduction of gears I36 and I31 1' preclude. the final stopping of the cam I 5. in a r 45 -the'spring I may" have: become unwound, the

position to. close the contacts I3; and I41 asishown in Fig. 11 whereby-upon supp'ly ofcurrent to the electric. motor He, no: matter toawhat degree winding motor II? will start to run'and' will con I tinueits winding. action until. the free turning V of epicyclic gearsv I36 and I'3i1 has effected the engagement of pins I39- and I40 afzterwhich the dog arm I35 'wil l rotate: in unison with gear 35' though locked thereto, the pins I25" and I26.

henceacting" in the same? way and for the same purpose as pins; I25; I26 in Fig. 4 heretofore explained; r

7 While .Fig. 2. shows. the: winding wheel 25, spring III", and time wheel '26i concentric with and; carried by the arbor 231, the accomplishment pointed out in. these improvements is as possible to an. arrangement of the mechanism whereby the parts recited. are neither concentric with nor carried by theyarbor 21.' They may be placed 1 on an. entirely separate spindle and the remain' ing partsincluding those shown in Figs.;4' to 12 inclus'ivemay remainconcentric" with and car- 1 ried; by the arbor 21. In such modification gears Hand 26 might be: retained upon: the arbor .21

r and; equivalent gears respectively enmeshed with same: carried by the-auxiliary spindle for the power-spring. abovereferred. to.

In the action of. the winding and unwinding of the; spring: I0 by: the: movements of; parts depicted in Figures '8 to 12;, inclusive, it may be mentioned that whenever" the winding, pin I25 or: I25." is. rotating td efiect. winding. the shaft means with one of said wheels to augment. the

I221. is also rotating and inthe same direction as pin I25 but at a lower rate of speed as retarded by the time keeping .escapement I2. The dura tion of each running of 7 motor II to wind is therefore a function of the relation ofjthese two. speeds and also. a function of the arcuate extent of the conductive piece I 3I carried by the cam I.5.. By varying. these two factors, which would. mostcommonly .be. done by' varying the speed: of the winding. motor II or its gearratio to they winding gear 25. or 25., or by varying the. arouate extent of the. piece I3I, the amount of winding that be imparted to spring I0 at each intermittent running of motor II can be determined. It isuthus possible to construct the 15 parts so that however far unwoundmay have become the spring I0 through failure of the motor II to. wind atv its intended time, when. motor II is. again made capable of winding it will at. a single run continuously wind the. spring 201 I0 until it is fully wound as in normal opera.- tion,v or it is possible; to; construct, the. parts; so that however far. the unwinding ofspring I0 if below the operating range of winding, no

single period of runningjof motor. II: will ima bereached by successive. accumulative runs of the motor II. For instance; while the shaft I21 be sure to make. contact; as in Figure 9 a each time it completes one: revolution and thus start the winding, the winding. maycontinue only long enough to be sure to effect. say, two or more complete revolutionsiiof the gear 25 or 25 before the slow travel. of the cam. I5 as im-' pelledf'by the time arbor pin 21' shall act to break'the circuit; between contacts I 3 and I4. This excess of; say, one winding revolution of pin. I25 over each corresponding unwinding revolution of pin I21, builds: up accumulatively until the; normal operating condition and degree of winding is finally resumed.

' Our invention will be understood to reside in all majoreombinationsof. a completely organized self-winding clock. and time switch which are made possible for the first time by the particular features ot such-organizations herein. dis closed and claimed and the following claims contemplate thesubstitution of equivalents'not specifically mentioned herein. 1

We: claim:----

'1'. Means to limit. the rotati've movement of' a spring; winding wheel relative to aspring. driven wheel, including in a combination with a: spring for storing power, a spring winding wheel connected to one. end ofsaid spring and avspring' driven-wheel: connected to the other end of said spring, separablestop means motivated in part. by one wheel and in partby the other wheel and engagable for limiting: relative movement between'said wheels in one directiongamf epicyclic gearing; connecting a part ofsaid stop number oif limited turnsv of eaclrv wheel relative to the; other, said; gearing including two nonmutilated-complete and intermeshed gears respectively carrying stopmembers: adapted to engage only after a; plurality of revolutionsof each; gear. j

2;. Means tolimit the rotativemovement of a spring windingwheel relative to a spring driven wheel, including. in'combination with a spring forfstoring. power, a spring winding wheel. con- 7 nected to impel one end of said spring and a spring driven wheel connected to be impelled by the other end of said spring, inter-engaging stop means moving in part with one of said wheels and moving in part with the other wheel for limiting relative movement between said wheels, and an epicyclic train including two complete unmutilated gears intermeshed and of tooth ratio to permit a number of turns of each of said intermeshed gears before a given point on one gear returns to co-incidence with a given point on the other gear, and means to check the relative movement of said intermeshed gears when the said given points thereon arrive at co-incidence, thereby to lock said train as a factor in limiting the relative movement between said winding and said driven wheels.

3. In a self-winding movement, the combination with a power storing spring, retarding gear connected to be impelled by said sprin and electrically driven gear connected to wind said spring, of circuit controlling means for starting and stopping said; winding gear including a floater carrying an arcuate part of conductive material and circuit terminals stationed in circumferentially spaced relation to be conductively bridged by said conductive material in certain rotative positions of said floater, and devices to prevent travel of said floater from said positions until the winding gear winds said spring. 4. In a self-winding movement as described in claim 3 connections whereby the devices which prevent travel of the floater are rotatively associated with said winding gear in a way to permit more than a full turn of said devices relative to said winding gear.

WILLIAM MUIR.

HERBERT C. SNOW. 

